Carburetor



Patented Apr. 14, 1931 PATENT OFFICE LEOPOLD PODSZUS, 0F BERLINGHARLOTTENBURG, GERMANY CARBURETOR Application filed. July 21, 1928, Serial No.

My invention relates to carburetors of the type described. in'iny copending patent application Serial No. 209,803, filed August 1, 1927. It is an object of my present invention to improve a carburetor of this type.

To this end, instead of a throttle valve which is adapted to reciprocate axially with respect to the casing of the carburetor, as shown in the said prior application, I provide a throttle valve of the usual rotary type, and means for operatively connecting the throttle valve with a piston for controlling the fuel valve.

In the carburetor described in the said prior application the fuel valve is controlled by a piston which is influenced by the suctionof the engine, and the stroke of the fuel valve is regulated by a stop on one arm of a double-armed lever the position of which is regulated in conformity with the position of the air inlet valve so that upon the air inlet valve opening wider the stroke limit of the piston and consequently that of the fuel valve, is extended and the supply of fuel is increased in proportion. A one-armed lever is provided for transferring the movement of the control piston to the fuel valve, the piston engaging the longer arm, and the fuel valve engaging the shorter arm of the lever. The stroke of the control piston is limited by the stop on the double-armed lever.

I have found that in carburetors of this general type the operation is much improved and a thoroughly uniform regulation for noload conditions is obtained by providing a rotary air inlet valve instead of the reciproeating valve in the carburetor according to my said copending application. Preferably the valve is a normal throttle valve and with a valve of this type a very simple operative connection of the throttle valve and the double-armed stop lever may be efieeted, for instance, by connecting the throttle and the stop lever by a system of levers, but in a preferred embodiment of my invention I provide a cam on the shaft of the throttle valve by which the stop lever is adjusted, and I may provide means for varying the effective stroke or eccentricity of the cam.

In the drawing affixed to this specification 294,365, and in Germany August 13, 1927.

and forming part thereof a carburetor embodying my invention is illustrated dia grammatically by way of example.

In the drawing F 1 is an elevation of the carburetor, partly in section through the axes of the fuel valve and the control piston,

Fig. 2 is a section on the line II-II in Fig. 1,

Fig. 3 is an elevation of the carburetor,

Fig. l is a plan view of the one-armed lever intermediate the fuel valve and the control piston,

Fig. 5 is an elevation of the control piston with the parts making up its piston rod separated, and V Fig. (5 is an elevation, partly in section, of the cam on the shaft of the throttle valve.

Referring now to the drawing, a is the casing of the carburetor which is connected to the suction chamber of an engine, not shown, by a suitable flange a, f is a throttle valve which is carried to rotate in the intake pipe (1 of the carburetor on a shaft 6, e is a lever for regulating the throttle f, b is a fuel jet, and l) is the choke or Venturi tube in the upper end of the casing a. It will appear that, as viewed in the direction of the flowof air toward the engine, the throttle f is not arranged at the rear of the choke tube and the nozzle 5, as usually, but in ad- Vance of these parts.

0 is a casing secured to one side of the carburetor a, n is a fuel valve in the casing, g is a pipe or passage extending from the seat of the fuel valve toward the jet 5, Z is a passage formed in the body of the jet in line with the pipe g, it is an air inlet pipe connected with a passage h which extends to the seat of the fuel valve n, h is a check valve at the end of the pipe h, and h" is a spring which tends to hold the valve /i on its seat.

0 is a one-armed lever which is fulcrumed in a bore of the casing 0 at 25 in a plug 15 and adapted to be engaged by a pin on the lower end of the fuel valve n as described in my said copending application, 79 is a control piston in a chamber of the casing 0 hav ing a perforated cap 1", 19 is the upwardly extending rod of the piston, which, as will piston p which is resting on the cap 1'.

appear from Fig. 5, is bored at its upper end for the reception of a stud 19 on an upward extension of the rod. The lever 0 is forked at its free end as will appear from Fig. 4, and is adapted to bear on the upper end of the rod 20 which is preferably rounded or beveled at this point, 8 is a doublearmed lever which is fulcrumed about a pin 8 in a bracket of the casing 0, z is an adjustable stop on the horizontal arm of the lever in line with the piston rod extension 79 w is a cam on the shaft 6 of the throttle valve 7, m is an extension of the bell-crank lever s, and s is a spring tending to hold the extension an engaged with the cam w, the stop a is held in position by a spring catch, not shown. The cam '11) is slotted as best seen in Fig. 6 and seated on a square 6 of the shaft 0, 'w is a threaded spindle which engages a threaded hole in the shaft 6 orin the square 6 and is held on thevcam w against axial displacement, and w is a nut for turning the spindle w so as to vary the position of the cam with respect to the axis of the shaft'e, and consequently its eccentricity E. I v

g is a suction passage connecting the chamber of the piston '79 with the casing a as willappear from Figs. 1 and 2.

With the parts in the initial position as illustrated in Fig. 1, the fuel valve a is permitted to rest on its seat so as to interrupt the supply of fuel to the jet b-hy the control The stop a is so adjusted as to permit the control piston p to perform a small stroke with the throttle valve 7 closed, that is, under no-load conditions, so that the fuel valve a may be operated under these conditions to admit the small amount of fuel required. When the throttle f is opened the position of the stop 2: with respect to the upper end of the extension 2 is varied, and it will be understood that when the cam w is adjusted on the shaft e of the throttle and the stop a is adjusted in the lever s, a given position of the stop .2 and consequently a given maximum elevation of the fuel valve 92 willcorrespond to any position of the throttle f. The suction from the engine draws fuel from the seat of the fuel valve 12 through the jet and at the same time causes the-valve h to open against the pressure of its springh" so that air-is mixed with the fuel and partly atomized. Itsatomization is completed by the flow of primary air in the choke tube 12. The flow of prisure in the chamber of the control piston '20 which thereupon is lifted from its seat by the pressure of the air entering through the perforated cap 1", and raised as far as permitted by the stop .2.

It will be understood that by increasing the eccentricity E of the cam to through the medium of the spindle w the stroke limit of the piston 19 and consequently the elevation of the fuel valve 17., are increased in proportion. The variation of the eccentricity E may be determined, for instance, by the fuel employed and the adjustment ofthe cam w may be facilitated by marks on the cam and a mark on the square 6'.

I Wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obviousv modifications will occur to a person skilled in the art.

I claim 1. A floatless carburetor having a fuel valve, a control piston adapted to be influenced by the suction in said carburetor, means operatively connecting said control piston and said fuel valve, a rotary air inlet valve, a shaft on said valve about which it is fitted to rotate, a cam on said shaft, a double-armed lever pivoted on the casing of said carburetor, and means for applying one armof said lever directly to said cam, its other arm constituting a stop for said control piston.

2. A floatless carburetor having a fuel valve, a control piston adapted to be influenced by the suction in said carburetor, means operatively connecting said control piston and said fuel valve, a rotary air inletvalve, a shaft on said valve about which it is fitted to rotate, a cam on said shaft, means for adj usting said cam radially with respect to said shaft, a double-armed lever pivoted on the casing of said carburetor, one arm of said lever being operatively connected withsaid cam, and its other arm constituting a stop for said control piston.

In testimony whereof I aflix my signature.

LEOPOLD PODSZUS.

. mary air also causes a reduction of the pres- 

